In accordance with that, the expression of KGF and KGFR could be directly correlated to epidermal proliferation of MEC tissue [241, 275, 276] as well as to proliferation of stem/progenitor cells [273, 274] which might also explain the correlation between KGF/KGFR and pathogenesis, as well as clinical recurrence of MEC after surgery [264, 275]. The gene discussed is FGFR2; the disease is mucoepidermoid carcinoma.